Safety lock



March 19, 1963 A. E. MINTZ 3,081,616

SAFETY LOCK Filed Dec. 21, 1960 26 I IPI l Al berf E. Minrz INVENTORj/wym 2 ATTORNEY hired drama This invention relates to safety locks andmore specifically, it relates to safety locks of the door chain typewhich may be locked and unlocked on one side of a door by a personwithout a key and which may be locked and unlocked on the other side byan authorized person with a key.

In my co-pending application, Serial No. 718,035, filed February 27,1958, and which matured December 27, 1960, into Patent No. 2,966,053, ofwhich this is a continuation-in-part, there is disclosed a casingattached to a door frame and a chain releasably mounted to the inside ofa door. The chain had a locking plug at the opposite end which wasconnected to the casing and required a key to separate it therefrom. Thechain was of such length that the door could be partially opened to theextent that a key could be passed through from the outside to unlock andremove the plug from the casing.

The safety lock comprising the present invention is similar in principleto that of my co-pending application except that in the present instancethe locking plug remains connected to the casing on the door frame andthe locking arrangement secures the chain to the plug or permitsseparation therefrom as desired. The locking mechanism includes a chainreceiving means which is held in locked position by a retention portionpositioned in an opening in the casing. In one form this permits the useof an ordinary padlock to be used as the plug to which the chain may beattached and detached. Since this makes the plug readily available fromcommercial sources at prices much less than the cost of special lockingplugs, the price of the present safety lock becomes quite competitivewith conventional door chains that does not have the advantage ofpermitting opening from the outside by a person with a key.

FIGURE 1 is a perspective view of the safety lock of the door chain typeas viewed from the side of the door to which it is mounted, and

FIGURE 2 is a vertical cross-sectional view of the casing.

Referring now to FIGURE 1, there is shown a fragmentary portion of adoor and door frame 11. The door has a knob 12, and the usual door lockswhich are not shown in the drawing.

In the preferred embodiment of the invention a door chain 13 is shownattached at one end 14 to the slide part 15 which engages a slot 16 in astandard chain bracket 17 secured to the door .10. The length of thechain 13 is such that with the other end 18 afiixed to the door frame 11, the slide part 15 cannot be released from the bracket 16 until thedoor 14} is substantially fully closed.

The chain end 18 is afiixed to door frame 11 through the frame mountedcasing 19 having an inverted padlock 2% contained therein. End 18 of thechain is shown engaging the padlock loop 21. The casing '19 is open atthe top to permit insertion of a key into the lock of the padlock torelease the padlock loop 21 so that the end 18 of the chain may bereadily removed.

It should now be apparent that the unlocking of the padlock and freeingof the end 18 of the chain may be easily accomplished from the otherside of the door by opening the door within the limits prescribed by thechain, and then inserting the proper key in the con- 3,681,615 PatentedMar. 19, 1963 veniently located keyhole of the padlock at the upper endof the casing. Likewise, upon leaving the house, the chain end may bereadily placed over the padlock loop and the loop snapped shut by aperson on the outside, so that the opening of the door will again berestricted by the chain.

It also should be apparent that with the padlock 20 locked, the slidepart 15 and bracket '17 function in the manner of conventional doorchain locks, permitting a person on the inside to lock and unlock thedoor as desired without resorting to using a key in the padlock.

It will be understood that the invention is not to be considered aslimited to the use of a slide and bracket at the other end of the chainsince the end 14 of the chain could be secured to the door in a fixedposition if desired. The use of the slide and bracket, however, providesgreater convenience for the householder by making it possible to releasethat end of the chain in the conventional manner. Also, if desired, thecasing could be secured instead to the door with the other end of thechain fastened to the door frame. H

In FIGURE 2, the casing 19 is shown in cross-section to better show theattachment of the padlock 20. Here an opening 22 extends through thecasing 19 and is adapted to receive the padlock 20 with the padlock loop21 extending downwardly and to permit insertion of the key 23 at thetop. The casing is thus preferably about the same length as the body ofthe padlock.

As shown, the axis of the opening 22 preferably slants inwardly at thebottom toward mounting plate 24. This provides more clearance from thewall for rotating the key 23 and slants the padlock loop 21 somewhatnearer the mounting plate. This provides an unusual advantage in thatwhen the loop 21 is opened, the weight of the chain 13 being slightlyoff center toward the free end 25 causes it to turn toward the door tofacilitate easy removal of the end of the chain therefrom.

The padlock may be retained in the casing by some means such as retainerscrew 26 inserted through an opening 27 in the mounting plate 24 andinto a small recess 28 in the body of the padlock 20. The mounting platemay be attached to the door frame by means of screws 29, 36, one ofwhich is not perpendicular to the plate 24 for greater fasteningsecurity.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto as many variations will be readily apparent to thoseskilled in the art and the invention is to be given its broadestpossible interpretation within the terms of the following claims:

What is claimed is:

1. A safety lock comprising a chain with means for attachment to theinside of a door, a padlock releasably connected to said chain, a doorframe mounted casing having an opening therein for receiving the body ofsaid padlock in inverted position, means retaining said padlock in saidopening, said chain being of such length as to permit the door to bepartially opened to permit insertion from outside the door of a key intosaid padlock to free said chain therefrom when said door, chain, padlockand casing are connected.

2. A safety lock comprising a chain with means for attachment to theinside of a door, a padlock releasably connected to said chain, a doorframe mounted casing having an opening therein for receiving the body ofsaid padlock in inverted position, said opening being slightly slantedto position said padlock non-vertical, means retaining said padlock insaid opening, said chain being of such length as to permit the door tobe partially opened to permit insertion from outside the door of anunlocking means into said padlock to free said chain from the 3 loop ofsaid padlock when said door, chain, padlock and casing are connected.

References Cited in the file of this patent 23 UNITED STATES PATENTS 521844 2,816,431 Harney Dec. 17, 1957 22,135

2,881,611 Callegari Apr. 14, 1959 354, 47 2,966,053 Mintz Dec. 27, 196042- FOREIGN PATENTS Germany Jan. 27, 1903 Great Britain July 22, 1911Great Britain Mar. 15, 19 12 Great Britain Mar. 13, 19 13 Great BritainOct. 7, 19 11 Great Britain Aug. 13, 1931

2. A SAFETY LOCK COMPRISING A CHAIN WITH MEANS FOR ATTACHMENT TO THEINSIDE OF A DOOR, A PADLOCK RELEASABLY CONNECTED TO SAID CHAIN, A DOORFRAME MOUNTED CASING HAVING AN OPENING THEREIN FOR RECEIVING THE BODY OFSAID PADLOCK IN INVERTED POSITION, SAID OPENING BEING SLIGHTLY SLANTEDTO POSITION SAID PADLOCK NON-VERTICAL, MEANS RETAINING SAID PADLOCK INSAID OPENING, SAID CHAIN BEING OF SUCH LENGTH AS TO PERMIT THE DOOR TOBE PARTIALLY OPENED TO PERMIT INSERTION FROM OUTSIDE THE DOOR OF ANUNLOCKING MEANS INTO SAID PADLOCK TO FREE SAID CHAIN FROM THE LOOP OFSAID PADLOCK WHEN SAID DOOR, CHAIN, PADLOCK AND CASING ARE CONNECTED.